The continuing development and refinement of empirically supported interventions to increase participation in post-treatment aftercare and promote sustained abstinence from illicit drug use is a priority for the addictions field. Typical models of drug abuse intervention have intensive periods of "treatment" followed by a less intensive, poorly defined "aftercare" period. Frequently, patients involved in the intensive phase of treatment show a reduction in, or complete abstinence from, the target and other drug use. However, when the treatment intensity is decreased during the aftercare period, relapse and readdiction are common. For drug abuse treatment to provide the desired result of long-term abstinence, it is important to develop strategies that will enhance the effectiveness of aftercare and/or continuity-of-care approaches. Moreover, such interventions must be inexpensive and relatively easy to implement to be portable to the "real world" setting of community-based programs. We will develop and compare the efficacy of four low-cost, telephone support protocols for patients who have completed the intensive phase of a structured, outpatient stimulant abuse treatment protocol. Participants will be 500 patients who have successfully completed the 4-month Matrix Outpatient Model of stimulant abuse treatment. They will then be randomly assigned to one of five aftercare-counseling conditions (each with n=100): (1) unstructured/non-directive, (2) unstructured/directive, (3) structured/non-directive, (4) structured/directive, or (5) standard referral to aftercare without telephone counseling (control). The two structured conditions are based on the behavioral "prompts" identified by Farabee et al. (2002) as being associated with drug avoidance. In the non-directive conditions, patients will state their own goals and how they intend to achieve them. In the directive conditions, the counselor will provide specific recommendations for the adoption of as many drug-avoidance activities as possible. Certain patient personality traits or styles will also be assessed for their possible interaction with the telephone counseling dimensions. Outcomes will be tracked at 6 and 12 months following completion of primary treatment and will include measurement of participation in drug-avoidance activities (including aftercare participation), as well as self-reported and objective measures of substance use and associated prosocial behavior change.